Sleep disorders are increasingly common, especially in old age. This is also true for Persons with Intellectual Disability (PwID), that over the last two decades have shown a significant increase in life expectancy.
Dr. van de Wouw and his colleagues from the Department of Medicine of Intellectual Disability at Erasmus Medical Center in Rotterdam (Netherlands) have recently conducted a review of the scientific literature produced from 1990 to 2011 on the characteristics of sleep disorders in adults and the elderly with DI. In particular, the authors collected data on prevalence of sleep disorders, related factors, and treatment.
A slightly modified version of the checklist SIGN-50 was used to assess the quality of evidence in all articles.
Of the 50 studies included in the systematic review only one proved to be of high quality, 14 were classified as 'well done', 14 were 'well-conducted but with a high risk of bias' and 21 were 'non-analytical'.
According to the literature, the prevalence of sleep disorders in adults with ID seems to vary between 8.5% and 34.1%. In the most severe forms it reaches 9.2%. The factors most frequently associated with the presence of sleep disorders were: problem behaviors, respiratory disease, vision problems, psychiatric disorders, and intake of psychotropic drugs, especially anti-epileptics.
Only two studies have evaluated the effects of various treatments on large samples, and suggest that non-pharmacological interventions may be effective.
Data concerning PwID in the elderly are scarce. van de Wouw and colleagues conclude that scientific research on the prevalence, associated factors, and treatment of sleep disorders in adults and seniors with ID has focused on data obtained from subjective evaluations. In addition, the definitions used to describe a sleep disorder are not uniform, and factors associated with eating disorders have been identified mainly through correlation statistics.
In order to provide recommendations for clinical practice, further research is needed, including objective measurements and multivariate analyses.
The results of a previous epidemiological study, conducted by the Section of Medical Psychology at the University of Glasgow, suggest that in PwID serious sleep problems are often part of larger psychiatric disorders, which have not been detected or adequately examined in depth.
Translated from Italian by Francesca Rizzo Benvenuti and Megan Thompson
REFERENCES
- Boyle A, Melville CA, Morrison J, Allan L, Smiley E, Espie CA, Cooper SA. A cohort study of the prevalence of sleep problems in adults with intellectual disabilities. J Sleep Res 2010 Mar, 19 (1 Pt 1) :42-53.
- E van de Wouw, Evenhuis HM, Echteld MA. Prevalence, associated factors and treatment of sleep problems in adults with intellectual disability: A systematic review. Res Dev Disabled. 2012 Jul; 33 (4) :1310-32.